Selecting-switch



C. L. GOODRUM AND J. A. KROPP.

SELECTING SWITCH. APPLICATION FILED FB.27, 1917.

1,33%,750. Patented Mar. 23, 1920.

z.-,- s zissuen 1.

//7 V/7/0/S.' Char/es L 6004/41/71 John A. Krupp C. L. GOODRUM AND J. A.KR OPP.

SELECTING SWITCH.

APPLICATION FILED F554;, 1911-.

Patented Mar. 23, 1920'.

2 SHEEISSHET 2.

. o a g is O ll I l I Xmsn a 8 Nb M //4 yen/0K3 (/4 ar/es Z. G'wdramJohn A. Aro vp.

, UNITED STATES PATENT onrron.

CHARLES L. GOODRUIVII, or BnooKLYiLnnvv YonK, Ann JOHN A. trader, or OAKPARK,

ILLINOIS, nssrenons no wnsrnaiv nLncrnIc ooMrANY, inoonronaren, on newYORK, 11. Y., A CORPORATION or NEW YQR-K.

SELECTING-salmon.

Specification of Letters Patent. P t ted IiIa1-.23, 1920.

Application filed February 27, 1917'. Serial No. 151,226.

To all whom it may concern:

Be it known that we, CirAnnns L. Goon- RUM and JOHN A. Knorr, citizensof the United States, residing at Brooklyn, in the county of Kings andState of New York, and at Oak Park, in the county of Cook and State ofIllinois, respectively, have invented certain new'and usefulImprovements in Selecting-Switches, of which the following is a full,clear, concise, and exact description.

This invention relates to an improvement in selecting switches.

The present invention has for its purpose the novel construction andarrangement of parts of a selecting switch which shall provide astructure materially reduced in size, and one which shallbe eflicient inoperation and economical to construct, install and maintain.

Another feature of this invention is the provision of novel. means forcontrolling a mechanical relay, such means being simple in construction,and positive and accurate in operation.

Referring to the drawings, Figure 1 is a side elevation of the improvedselecting switch, certain parts being broken away for clearness inillustration and description; Fig. 2- is a plan view of the same; Fig. 3is a front elevation; Fig. 41 is a sectional plan view taken on the linel -4 of Fig. 1; Fig. 5

is a'section on the line 5-5 of Fig. 1, certain parts of the structurebeing broken away for clearness in illustration and description; Fig. 6illustrates diagrammatically an operating circuit for the improvedselecting switch.

Referring in detail to the drawings, 10 designates a brush-carryingelement or shaft mounted for vertical and rotary movement in thesupporting structure (not shown). The shaft carries brushes 11. whichengage contacts 12 of a: switch bank 13. The shaft 10, near itsintermediate portion, is provided with vertical ratchet teeth 14: whichare cut by a vertical slot 15. In depth this slot is cut to the surfaceof the shaft and is sufficiently wide to permit unobstructed elevationof the shaft after its first rotary step. The vertical ratchet teeth areengaged by a vertical elevating pawl 16 carried. by the armature 17 of aprimary motor magnet 18. The motor magnet 18 is provided with a frameli)which is connected to the supporting structure and which 1s providedwith a catch 20 normally engaged by a projection on the vertical pawl16. The framelS) also carries a stationary holding dog as, which is inthe vertical slot 15 during the elevation of shatt 10 and engages one ofthe vertical ratchet teethon rotation of the shaft to sup port the shaftin its elevated position; The shaft 10 is also provided with rotaryratchet teeth 21 which are engaged by a pawl 22mried by the armature 23of a secondary magnet 24. It should be noted that the contacts 12 are sopositioned with respect to brushes 11, that the first rotary step of theshaft does not bring these elements into engagement. The secondarymagnet 24 is secured to the supporting structure in frame 26 (Fig. 1)which carries an arm serving to normally hold pawl 22 out of engagementwith the rotary ratchet teeth. 27 designates the release magnet whichremains energized during the interval in which the switch is beingutilized in establishing and maintaining a connection. with an armature28 to which is pivotally se- The release magnet 27 is provided cured thevertical holding dog 29 and the rotary holding dog 30. An escape magnet31 is provided with an armature 32 which controls the well-knownescapement members 33. These members 33 control the step-bystep escapeof an arm 34:. which actuates the block 35 of a mechanical relay or sideI switch. This bloclc is provided with the usual side-switch wipers-36which engage well-known side-switch contacts to control the operatingcircuits of the switch. It

should be noted that the arm 34L of the side- I switch block is placedunder tension as soon as the release magnet is energized. This isaccomplished in the following manner: A leaf spring 37 is attached atone of its ends to the armature of the release magnet, and its other endis secured to-the arm 3.4 by a link 38. It willv be understood that,during the operation of the switch, this leaf spring 37 places a tensionon the side-switch'arm 34-, such that this member is positively operatedunder the control of the escape ma net. When, however, it is desiredtorestore the switch to its normal position, the release magnet isdeenergized, and onthe retraction switch, thereby insuring the promptreturn of the side switch to its normal position. A coiled spring 39,secured at one of its ends to the shaft and at its other end to theframe, is placed under tension when the shaft is rotated from its normalposition. This spring insures the restoration of the shaft to its normalposition when the switch is released.

' Referring to the operation of the switch,

it is proposed to omit certain of the re lays formerly used instep-by-step selecting switches, and so to arrange the magnets of theswitch that they will perform the addi tional functions formerlyperformed'by rclays. When the calling line is extended to this selectingswitch, its vertical magnet is energized, thereby attracting itsarmature, which operates to close circuit-closing springs 40. Thesecircuit-closing springs control the operating circuit of the releasemagnet. This first encrgizati 011 of the magnet 18, however, does notelevate the shaft since the elevating pawl 16 is held out of engagementwith the vertical ratchet teeth by a stop which engages a projection 41car- 1 ried on the armature of the release magnet. The closing of thespring 40 energizes the release magnet 27 This magnet upon energizationattracts its armature,thereby moving the projection 41 out of the pathof the vertical pawl 16 and placing the vertical holding dog 29 inengagement with the Vertical ratchet teeth and the rotary holding dog 30in engagement with the rotary ratchet teeth. After'the first series ofdirective impulses, the escape magnet 31 deenergizes and the side-switcharm 34 under the tension of leaf spring 37 is escaped one step by theescapement members 38. The sideswitch wipers in their second positioncomplete an operating circuit for rotary magnet 24, which actuates itsarmature and the rotary pawl 22 to rotate the shaft during thetrunk-hunting operation. The holding dog 42 operates to hold the shaftin, its elevated position after the switch has made its first rotarystep. At the close of the conversation, when one of the parties hasreplaced his receiver, the releasemagnet 27, which has been energizedduring this period, has

its circuit interrupted and thereupon rctracts its armature. This movesthe vertical and rotary holding dogs out of engagement with the verticaland rotary ratchet teeth, and the spring 39 rotates the shaft until thestationary dog 42 encounters the slot 15, whereupon the shaft drops toits normal position;

Referring to the circuit arrangement as disclosed in Fig. 6, when thesubscriber at substation 5'0 removes his receiver from the switchhook,the brushes 51, 52 and 53 of a finder locate contacts 54, 55 and 56 ofthe calling line. The calling line is then tended to a selecting switchof the type herein disclosed and described. As soon as the line isextended to this selecting switch, primary magnet 1.8 is energized overa circuit which extends from grounded battery, left-hand winding of theprimary magnet 18, side-switch wiper 36 in its first position, brush 52,contact 55,substation apparatus 50, contact 54, brush 51, side-switchwiper 36 right-hand winding of primarymotor magnet 18, to ground. Magnet18 thereupon attracts its armature and completes an en ergizing circuitfor the release magnet 27, which magnet in this arrangement controls thesetting of the vertical and rotary holding dogs. The release magnet isenergized over a circuit which extends from grounded batter right-handwinding of magnet 27, normally closed contact 44, front contact andarmature of magnet 18, to ground. Release magnet 27 upon energization,attracts its armatures, and at its left-hand armatu completes a lockingcircuit which extends from grounded battery, right-h and winding ofrelease magnet 27, front contact and lefthand armature of release magnet27, front contact and armature of primary motor magnet 18, to ground. Itshould here be noted that the normally closed contact 44 is opened assoon as the shaft takes its first vertical step. 1

When the calling subscriber operates his sending device to transmitimpulses corresponding to the desired number, the armature of magnet 18is vibrated to elevate the brush shaft and in so doing, completes anenergizing operating circuit for the secondary magnet 24, which in thisarrangement serves to control the operating circuit of the escape magnet31. The circuit for the secondary magnet extends from grounded battery,magnet 24, normally closed contact 43, front contact and right-handarmature oi release magnet 27 back-contact and armature of primarymagnet 18, to ground. Secondary motor magnet 24 is thereupon energizedand attracts its armatures. It should be remembered that the contacts 12and brushes 11 ar-e'so positioned that they are not brought intoengagement by the first ac tuation of the left-hand armature of magnet24. At its right-hand armature, magnet 24 completes an energizingcircuit for the escape magnet 31, which circuit may be traced fromgrounded battery, escape magnet 31, conductor 57, side-switchwiper,36'?, front contact and right-hand armature of magnet 24, toground. At the close of the series of directive impulses from thesending device, magnet 18 attracts its armature for a relatively longinterval, thereby interrupting at its back contact the energizingcircuit ofthe secondary magnet. This magnet, although slow to release,during this relatively long interval retracts its armatures, and at itsright armature and front contact interrupts the energizing circuit ofthe escape magnet. The deenergization of this escape magnet operates tomove the side-switch wipers to their second position.

Then the side switch moves into the second position, the secondarymagnet is operated over a self-interrupting circuit which extends fromgrounded battery, secondary magnet 24, left-hand armature and backcontact of magnet 24;, side-switch wiper 36 in its second position,armature and back contact of escape magnet 31, to ground. The secondarymagnet continues to operate until the test brush 11 encounters agrounded test terminal 12, whereupon the escape magnet is energized overthe following circuit: grounded battery, escape magnet 31, conductor 57,side-switch wiper 36 in its second position, test brush 11, test contact12, to ground. The escape magnet 31 Y attracts its armature and therebyinterrupts the operating circuit of the secondary magnet, and moves theside-switch wipers into their third or talking position. The line relayof the succeeding selecting switch (not shown) immediately removes theground condition from contact 12 so that the escape magnet 31 isdeenergized, thus preventing the release of the switch.

If the calling party replaces his receiver before the side-switch wiper36 has moved into its third position, the release magnets at thepreceding selecting switches will have their operating circuitscompleted over contact 56, brush 53, side-switch wiper 36 in its firstor second position, conductor 58, right-hand armature and back contactof magnet 27, armature and back contact of magnet 18, to ground.

At the close of the conversation, when the calling party replaces hisreceiver on the switchhook, circuit conditions are brought about whichreplace the ground condition on test contact 12, as indicated in thepatent to Goodrum, No. 1,231,013, issued June 26, 1917. The escapemagnet is energized over a circuit which may be traced from groundedbattery, escape magnet 31, conductor 57, side-switch wiper 36 in itsthird position, test brush 11, test contact 12, to ground. An energizingcircuit for the, release magnets of the preceding selecting switches, inparallel with the last described circuit, extends from contact 56, brush53, side-switch wiper 36 in its third position, conductor 57,side-switch wiper 36 in its third position, test brush 11 and groundedtest contact 12. The escape magnet thereupon attracts its armature andinterrupts at its back contact the energizing circuit for the releasemagnet, which may be traced from grounded battery, right-hand winding ofrelease magnet 27 left-hand winding of this same magnet, side-switchwiper 36 in its third position, armature and back contact of escapemagnet 31, to ground. The left-hand winding of release magnet 27 is ofrelatively high resistance as compared to its right-hand winding. Thiscauses the release magnet, when its energizing circuit extends throughboth of its windings, to deenergize quickly on any interruption of itsoperating circuit. \Vhen the calling party replaces his receiver -on theswitchhook, magnet 18 is deenergized and retracts its armature, and whenthe re lease magnet 27 has retracted its righthand armature, anotherenergizing circuit for the release magnet of the preceding selectorswitches is completed as above described over contact 56, test brush 53,side-- switch wiper 36 now restored to its first position, conductor 58,right-hand armature and back contact of release magnet 27, back contactand armature of primary magnet 18, to ground.

The normally closed contact 4C3, which is opened on the first rotarystep of the shaft, prevents the shaft from being again stepped until theswitch has been restored to its normal position.

\Vhat is claimed is:

1. In an automatic switch, passive contacts, active contacts, a memberto which said active contacts are, secured, said member being mountedfor group and line selecting movements, means for operating said member,circuit-controlling means, a member for placing the operating parts ofsaid circuit-controlling means under tension while being actuated andfor restoring said circuit-controlling means to normal position.

2. In an automatic switch, passive contacts, active contacts, a memberto which said active contacts are secured, said memher being mounted forvertical and rotary movement, means for operating said member, amechanical'relay, and a member for placing the operating parts of saidrelay under tension while being actuated and for restoring said relay tonormal position.

3. In an automatic switch, passive contacts, active contacts, a memberto which said active contacts are secured, said member being mounted forprimary and secondary movements, operating means for said member, amechanical relay, means controlling the release of said member to itsnormal position, and means associated with said release controllingmeans for placing the operating parts of said mechanical relay undertension while actuated.

4-. In an automatic switch, passive contacts, active contacts, a memberto which said active contacts are secured, said member being mounted forvertical and rotary movements, operating means for said member, amechanical relay, means controlling the release of said member to itsnormal position, and means associated with said release-controllingmeans for placing the op erating parts of said mechanical relay undertension while actuated. I

5. In an automatic switch, passive contacts, movable brushes mounted toengage said passive contacts, a shaft to which said brushes are secured,said shaft being mounted for movement in two directions,

means for operating said shaft, releasemechanism including anclectromagnet provided with an armature, holding elements carried bysaid armature, said holding elements operating to maintain said shaft inits actuated position, said electromagnet being actuated during thedirectiveoperation of said shaft.

(3. In an automatic switch, passive contacts, active contacts, a memberto which said active contacts are secured, said memher being mounted forprimary and secondary movements, operating means for said member, arelease mechanism including an electromagnet provided with an armature,a mechanical relay, and means controlled by the actuation of saidarmature for placing the operating parts of said mechanical re lay undertension.

7 .-In an automatic switch, passive contacts, active contacts, a shaftto which said contacts are secured, said shaft being mounted formovement in two directions, primary stepping means for operating saidshaft in one direction, secondary stepping means for operating saidshaft in a second direction, means controlling the sequence of operationof said primary and secondary stepping means, means for releasing saidshaft, and means for preventing said shaft from being stepped on thefirst actuation of said primary stepping means.

8. In an automatic switch, passive contacts, active contacts mounted forgroup and line selecting movements, means for operating said activecontacts, a circuit controlling device, a resilient member for placingthe operating parts of said circuit controlling device under tensionwhile being actuated and while being restored to its normal position,and means for actuating said resilient member.

9. In an automatic switch, passive contacts, active contacts mounted forvertical and rotary movement, means for actuating said active contacts,a mechanical relay, a resilient member for placing the operating partsof said relay under tension while being actuated and while beingrestored to normal position, and means for actuating said resilientmember.

In witness whereof, I hereunto subscribe my name this 18th day ofFebruary A. D.,

7 CHARLES L. GOODRUM. In witness whereof, I hereunto subscribe my namethis 20 day of Feb. A. D., 1917.

JOI II A. KROPP.

